if a metal has a bcc crystal structure, the coordination number is 8,because `:`

Options

A. each atom touches four atoms in the layer above it, four in the layer below it and none it its own layer
B. each atom touches four atoms in the layer above it, fourth in the layer below it and one its own layer
C. two atoms touch four atoms in the layer above them, four in the layer below them, and none in their own layer.
D. each atom touches eight atoms in the layer above it, eight in the layer below it, and none in their own layer.0